This is the easiest method I found to remove the injector electrical connectors; it is still a pain in the ass, but once you get the hang of opening up the springs (from the side nearest the fuel rail) you then slide in the small zip ties (pointy end down). If you don't use something to keep the springs "open" all you have to do is breathe on them wrong and they'll spring back and lock back onto the injector.
I also finally found a "procedure" over on big coupe forum that google had cached. I'll post it here for the group.
1. Remove Vent pipe - just in the way, block head end.
2. Remove the injector connector spring clips ( tricky bit #1)
(I don't recommend fully remove springs, you risk breaking the connector IMO. Just use the zip tie method)
3. Remove connector channel, plus wire to TPS. Fold out of way.
4. Remove start valve pipe, pressure regulator tube and flow/return pipes ( depressurize?)
(not sure what the start valve pipe is, might be M6 specific? I just removed the supply and return fuel hoses from the fuel rail)
5. Remove 2 10mm bolts holding fuel rail. Remove injector flat clips (tricky bit #2). Pull off fuel rail - pull hard and straight up?
6. Remove all except No 1 spark plug. Paper in plug holes as usual precaution
7. Turn over until No 1 compression felt at TDC.
8. Now it's safe to pull out injector on cylinder 1. Any bits at least do not fall into the cylinder. Presumably, if they do, then would have to remove the airbox, throttle bodies and manifold. Question, should I just remove the whole intake system, including the injectors and do it on the bench?
9. Assuming the answer is no, then after removing cyl 1 injector turn in firing order 153624 till each piston is at tdc. ( clean plastic rod down plughole) and remove injectors in that order.
10. All out and nothing fell into the cylinders, have a large drink.
11. Like it says - assembly is the reverse.